Hydrogen-eliminating porous structure ceramic fire-resistant material and preparation method thereof

Abstract

The application belongs to the field of ceramic fire-retardant materials, and specifically provides a hydrogen-removing porous structure ceramic fire-retardant material and a preparation method and application thereof, which comprises the following steps: 1) taking quaternary ammonium base solution, cellulose and a solvent, mixing them uniformly, then adding modified polysaccharide and amino acid derivative and continuing to mix, then filling in inert gas for foaming, then transferring to a coagulation liquid for shaping, and then washing to obtain a cellulose-based foam material; 2) soaking the cellulose-based foam material in a modified liquid, and then performing microwave heating treatment, then taking out, washing and drying to obtain a template material; 3) taking ceramic powder, water, ethanol, a binder, a rheological agent, a dispersing agent and a plasticizer, mixing them uniformly to prepare ceramic slurry, then immersing the template material in the prepared ceramic slurry, waiting for the ceramic slurry to uniformly wrap the template material, then extruding and discharging the excess slurry, and finally drying and sintering to obtain the porous structure ceramic fire-retardant material. The porous structure ceramic fire-retardant material prepared by the application has the advantages of high strength and good fire-retardant performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceramic fire-retardant materials, and particularly relates to a hydrogen-eliminating porous structure ceramic fire-retardant material and a preparation method thereof. BACKGROUND

[0002] The porous ceramic is endowed with various excellent performances such as high permeability, large specific surface area, low density, low thermal conductivity, sound absorption, high temperature resistance and corrosion resistance due to its rich pore structure. Therefore, the porous ceramic is widely applied in filtration separation, catalyst carrier, sound absorption, heat insulation and other fields. The use of the porous ceramic is determined by its pore structure, and the porous ceramic used as a heat-insulating, fire-retardant and fire-retardant material needs to have high heat-insulating, fire-retardant, heat-insulating and fire-retardant performances.

[0003] There are various methods for preparing the porous ceramic, and different preparation methods are selected according to the performance requirements of the material so as to achieve good expected effect. In recent years, the methods for preparing the porous ceramic mainly include the particle packing method, the template method, the foaming method, the gel casting method, the organic foam impregnation method, the freeze-drying method and the mixed pore-forming method. The organic foam impregnation method is a preparation process in which the special structure of the three-dimensional open-cell reticular skeleton of the organic foam body is used as a template, the prepared ceramic slurry is uniformly coated on the organic foam body, the excess ceramic slurry on the organic foam body is removed, and then the porous ceramic is obtained by removing the organic foam body through sintering, and the fire-retardant, fire-retardant and heat-insulating performances are excellent.

[0004] At present, the commonly used organic foam bodies include polyurethane, cellulose, wood, polyvinyl chloride and polystyrene. The porous ceramic prepared by the organic foam impregnation method can well control the pore structure characteristics and microstructure characteristics of the porous ceramic by selecting different templates, and the operation is simple and convenient. However, the porous ceramic prepared by the organic foam impregnation method has large deformation, low strength, easy structure collapse and limited pore size and pore type in the sintering process, which are limited by the shape of the organic foam body.

[0005] In addition, the porous ceramic can play a good protection role in the combustion process of fire accidents. However, when facing special hydrogen-containing combustible gas, the flammability range of the hydrogen-containing combustible gas is very wide, the ignition energy is extremely low, the diffusion speed is fast, the combustion temperature is high, and a large amount of free radicals are generated. In the face of such a complex high-temperature combustion environment, the existing porous ceramic cannot meet the protection requirements, and therefore it is urgent to develop a high-performance porous ceramic material. SUMMARY

[0006] In view of the above problems, in order to further improve the fire-retardant, heat-insulating and protective performances of the porous ceramic in the hydrogen combustion environment, the application provides a hydrogen-eliminating porous structure ceramic fire-retardant material and a preparation method thereof.

[0007] The application first provides a preparation method of a hydrogen-absorbing porous structure ceramic fire-resistant material, comprising the following steps:

[0008] 1) Take the quaternary ammonium base solution, cellulose, and solvent, mix them uniformly, then add the modified polysaccharide and amino acid derivative, continue to mix, then fill in inert gas to foam, then transfer to the coagulation liquid to shape, and after washing, the cellulose-based foam material is obtained;

[0009] 2) Mix deionized water, N-alkyl acrylamide, and fatty acid iron salt uniformly to prepare a pre-solution, then slowly add aluminum sulfate, urea, and unsaturated dicarboxylic acid into the pre-solution to prepare a modified solution, then soak the cellulose-based foam material into the modified solution, microwave heating treatment, then take out, wash, and dry to obtain a template material;

[0010] 3) Mix ceramic powder, water, ethanol, binder, rheological agent, dispersant, and plasticizer uniformly to prepare a ceramic slurry, then immerse the template material into the prepared ceramic slurry, wait for the ceramic slurry to uniformly wrap the template material, then extrude and discharge the excess slurry, and finally dry and sinter to obtain the product.

[0011] Further, in the step 1), the mass-volume ratio of the quaternary ammonium base solution, cellulose, and solvent is (65-70) mL:(10-15) g:(20-30) mL;

[0012] And / or, in the step 1), the solvent is one of DMF, DMSO, and DMAC;

[0013] And / or, in the step 1), the amino acid derivative is one or more of phthaloylglycine, palmitoylglycine, and N-benzoylglycine.

[0014] Further, the preparation method of the modified polysaccharide comprises the following steps:

[0015] a) Take the flaxseed gum solution, add polysaccharide and casein, stir until fully dissolved, and adjust the pH value to weak alkaline to obtain a mixed solution;

[0016] b) Add sodium tetraborate and β-mercaptoethanol to the mixed solution, react at a temperature of 85-95℃ for 60-80 min to obtain the modified polysaccharide.

[0017] Further, the polysaccharide is one or more of konjac gum, pectin, and xanthan gum.

[0018] Further, in the step 2), the mass ratio of deionized water, N-alkyl acrylamide, and fatty acid salt is 1:(0.1-0.15):(0.05-0.1);

[0019] And / or, in the step 2), the fatty acid iron salt is one or more of iron palmitate, iron stearate, iron oleate;

[0020] And / or, in the step 2), the N-alkyl acrylamide is one or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, N-octadecyl acrylamide;

[0021] And / or, the unsaturated dicarboxylic acid is one of fumaric acid, maleic acid, glutaconic acid.

[0022] Further, in the step 3), the ceramic powder includes alumina, zirconia, magnesia;

[0023] And / or, in the step 3), the binder is one of polyvinyl alcohol, sodium carboxymethyl cellulose, polyethyleneimine, silica sol, aluminum phosphate, borate, sodium silicate, potassium silicate;

[0024] And / or, in the step 3), the rheological agent is one of carboxymethyl cellulose, hydroxyethyl cellulose, bentonite, kaolin;

[0025] And / or, in the step 3), the dispersant is one of citric acid, sodium polymetaphosphate, polyacrylamide, polyvinyl alcohol, polyvinyl ether;

[0026] And / or, in the step 3), the plasticizer is one of talc, mica powder, dioctyl phthalate.

[0027] Further, the coagulation liquid includes the following raw materials in weight fractions: water 100-150 parts, sulfuric acid 5-10 parts, carrageenan 0.15-0.2 parts, cyclodextrin derivative 0.8-1.2 parts, nickel nitrate 1-3 parts, manganese nitrate 2-5 parts.

[0028] Further, the cyclodextrin derivative is prepared by a method including the following steps:

[0029] I) Imidazole-1-acetic acid is added to dichloromethane and stirred until completely dissolved, then oxalyl chloride is added, heated to reflux and reacted, and the solvent is removed to obtain imidazole-1-acetyl chloride;

[0030] II) The cyclodextrin is dissolved in DMF, triethylamine is added and mixed uniformly, then the DMF solution containing imidazole-1-acetyl chloride is slowly added to the system, fully reacted, then washed with acetone, then redissolved with deionized water, and dried to obtain.

[0031] Further, the cyclodextrin is one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin.

[0032] The application also provides a hydrogen-consuming porous structure ceramic fire-resistant material prepared by the above preparation method.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] 1、The application adopts quaternary ammonium base and solvent to blend and dissolve cellulose to form a heterogeneous cellulose dissolution system, and adopts inert gas foaming to prepare a three-dimensional pore structure. After adding modified polysaccharides and amino acid derivatives, the modified polysaccharides and amino acid derivatives can assist in enhancing the mechanical properties of the three-dimensional network structure of cellulose, thereby improving the subsequent ceramic slurry hanging, sintering forming performance, inhibiting the generation of adverse defects such as pore collapse and deformation, and increasing the skeleton strength and toughness of the porous structure ceramic.

[0035] 2、The application performs impregnation modification treatment on the cellulose-based foam material. On the one hand, aluminum ions and unsaturated dicarboxylic acids can be adsorbed and form a three-dimensional network of aluminum ion organic ligands in the presence of water and urea inside the material pore, and a porous foam alumina structure can be formed in the sintering process to further improve the porous structure skeleton strength. On the other hand, the iron salt of fatty acid forms active doping on alumina after sintering, and iron atoms can effectively eliminate free radicals generated in the combustion process of hydrogen-containing combustible materials through chain reaction. Moreover, since iron atoms are prone to agglomeration and aggregation into three-dimensional particles to lose activity, and the porous foam alumina can well inhibit the agglomeration of iron atoms, the addition amount of the iron salt of fatty acid can be increased to increase the doping concentration of iron and obtain better free radical elimination effect. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is an SEM schematic diagram of the hydrogen elimination porous structure ceramic fire-resistant material sample of Example 1 of the application.

[0037] Figure 2 It is an SEM schematic diagram of the hydrogen elimination porous structure ceramic fire-resistant material sample of Example 2 of the application.

[0038] Figure 3 It is an SEM schematic diagram of the hydrogen elimination porous structure ceramic fire-resistant material sample of the control group of the application.

[0039] Figure 4 It is an SEM schematic diagram of the porous foam alumina formed on the porous structure surface of the hydrogen elimination porous structure ceramic fire-resistant material sample of Example 2 of the application.

[0040] Figure 5 It is an SEM schematic diagram of the hydrogen elimination porous structure ceramic fire-resistant material sample of the control group of the application. DETAILED DESCRIPTION

[0041] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0042] Through a large number of experimental researches, in the face of the shortcomings of traditional cellulose porous templates, cellulose-based foam materials are constructed through a heterogeneous dissolution system, and modified polysaccharides and amino acid derivatives and aluminum ion organic ligands are introduced to improve the strength of the porous structure skeleton, and in addition, a proper amount of iron atoms can effectively eliminate free radicals, and the fire resistance and heat insulation performance are better.

[0043] Specifically, the present application provides a preparation method of a hydrogen-consuming porous structure ceramic fire-resistant material, comprising the following steps:

[0044] 1) Take the quaternary ammonium base solution, cellulose, and solvent, mix them uniformly, then add the modified polysaccharide and amino acid derivative and continue to mix, then fill in the inert gas to foam, then transfer to the coagulation liquid to shape, and after washing, the cellulose-based foam material is obtained;

[0045] 2) Mix deionized water, N-alkyl acrylamide, and fatty acid iron salt uniformly to prepare a pre-liquid, then slowly add aluminum sulfate, urea, and unsaturated dicarboxylic acid to the pre-liquid to prepare a modified liquid, then soak the cellulose-based foam material in the modified liquid, microwave heating treatment, then take out, wash, and dry to obtain the template material;

[0046] 3) Mix ceramic powder, water, ethanol, binder, rheological agent, dispersant, and plasticizer uniformly to prepare ceramic slurry, then immerse the template material in the prepared ceramic slurry, wait for the ceramic slurry to uniformly wrap the template material, then extrude and discharge the excess slurry, and finally dry and sinter to obtain the product.

[0047] Further, in step 1), the mass-volume ratio of the quaternary ammonium base solution, cellulose, and solvent is (65-70) mL:(10-15) g:(20-30) mL;

[0048] And / or, in step 1), the solvent is one of DMF, DMSO, and DMAC;

[0049] And / or, in step 1), the amino acid derivative is one or more of phthaloylglycine, palmitoylglycine, and N-benzoylglycine.

[0050] In some embodiments, the mass-volume ratio of the quaternary ammonium base solution, cellulose, and solvent in step 1) can be 65 mL: 10 g: 20 mL, 65 mL: 12 g: 20 mL, 65 mL: 15 g: 20 mL, 65 mL: 10 g: 25 mL, 65 mL: 10 g: 30 mL, 65 mL: 12 g: 25 mL, 65 mL: 12 g: 30 mL, 65 mL: 15 g: 25 mL, 65 mL: 15 g: 30 mL, 70 mL: 10 g: 20 mL, 70 mL: 12 g: 20 mL, 70 mL: 15 g: 20 mL, 70 mL: 12 g: 30 mL, 70 mL: 15 g: 30 mL. In general, the mass-volume ratio of the quaternary ammonium base solution, cellulose, and solvent is 70 mL: 12 g: 20 mL, and better experimental results can be obtained.

[0051] In some embodiments, the quaternary ammonium base solution is one or more of tetramethylammonium hydroxide solution, tetraethylammonium hydroxide solution, tetrapropylammonium hydroxide solution, and tetrabutylammonium hydroxide solution. In general, the quaternary ammonium base solution is tetrabutylammonium hydroxide solution, and better experimental results can be obtained.

[0052] In some embodiments, the cellulose is natural cellulose. More preferably, the natural cellulose is one or more of bamboo pulp, wood pulp, cotton pulp, straw fiber, and hemp fiber. In general, the cellulose is cotton pulp, and better experimental results can be obtained.

[0053] In some embodiments, the solvent is DMSO, and the amino acid derivative is N-benzoyl glycine, and better experimental results can be obtained.

[0054] In some embodiments, the mass ratio of the cellulose, modified polysaccharide, and amino acid derivative can be 1:0.1:0.05, 1:0.12:0.05, 1:0.135:0.05, 1:0.15:0.05, 1:0.12:0.06, 1:0.135:0.06, 1:0.16:0.06, 1:0.12:0.07, 1:0.135:0.07, 1:0.15:0.07, 1:0.12:0.075, 1:0.135:0.075, 1:0.15:0.075. In general, the mass ratio of the cellulose, modified polysaccharide, and amino acid derivative is 1:0.15:0.06, and better experimental results can be obtained.

[0055] Further, the preparation method of the modified polysaccharide comprises the following steps:

[0056] a) Take a flaxseed gum solution, add polysaccharide and casein, stir until fully dissolved, and adjust the pH value to weak alkaline to obtain a mixed solution;

[0057] b) adding sodium tetraborate and beta-mercaptoethanol into the mixed solution, and reacting at a temperature of 85-95°C for 60-80 min to obtain the modified polysaccharide.

[0058] Further, the polysaccharide is one or more of konjac gum, pectin, and xanthan gum.

[0059] Further, in the step 2), the mass ratio of the deionized water, the N-alkyl acrylamide, and the fatty acid salt is 1:(0.1-0.15):(0.05-0.1).

[0060] Further, in the step 2), the fatty acid iron salt is one or more of iron stearate, iron palmitate, iron stearate, and iron oleate.

[0061] Further, in the step 2), the N-alkyl acrylamide is one or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, and N-octadecyl acrylamide.

[0062] Further, the unsaturated dicarboxylic acid is one of fumaric acid, maleic acid, and glutaconic acid.

[0063] In some specific embodiments, when the polysaccharide is xanthan gum, the fatty acid iron salt is iron stearate, the N-alkyl acrylamide is N-hexadecyl acrylamide, and the unsaturated dicarboxylic acid is fumaric acid, a better experimental result can be obtained.

[0064] In some specific embodiments, in the step 2), the mass ratio of the deionized water, the N-alkyl acrylamide, and the fatty acid salt can be 1:0.01:0.005, 1:0.013:0.005, 1:0.015:0.005, 1:0.012:0.008, 1:0.015:0.008, 1:0.013:0.01, or 1:0.015:0.01. In general, when the mass ratio of the deionized water, the N-alkyl acrylamide, and the fatty acid salt is 1:0.015:0.008, a better experimental result can be obtained.

[0065] Further, in the step 3), the ceramic powder includes aluminum oxide, zirconium oxide, and magnesium oxide.

[0066] Further, in the step 3), the binder is one of polyvinyl alcohol, sodium carboxymethyl cellulose, polyethyleneimine, silica sol, aluminum phosphate, borate, sodium silicate, and potassium silicate.

[0067] Further, in the step 3), the rheological agent is one of carboxymethyl cellulose, hydroxyethyl cellulose, bentonite, and kaolin.

[0068] And / or, in the step 3), the dispersant is one of citric acid, sodium polymetaphosphate, polyacrylamide, polyvinyl alcohol, polyvinyl ether;

[0069] And / or, in the step 3), the plasticizer is one of talc powder, mica powder, dioctyl phthalate.

[0070] In some embodiments, the ceramic powder is generally composed of alumina, zirconia, magnesium oxide in a mass ratio of 1:1:0.2, the binder is sodium carboxymethyl cellulose, the rheological agent is bentonite, the dispersant is sodium polymetaphosphate, and the plasticizer is dioctyl phthalate.

[0071] In some embodiments, the solid content of the ceramic slurry can be 65%, 70%, 75%, 80%, and generally, when the solid content of the ceramic slurry is 75%, better experimental results can be obtained.

[0072] Further, the coagulation liquid comprises the following raw materials by weight fraction: water 100-150 parts, sulfuric acid 5-10 parts, carrageenan 0.15-0.2 parts, cyclodextrin derivative 0.8-1.2 parts, nickel nitrate 1-3 parts, and manganese nitrate 2-5 parts.

[0073] Further, the cyclodextrin derivative is prepared by a method comprising the following steps:

[0074] I) Imidazole-1-acetic acid is added to dichloromethane and stirred until completely dissolved, then oxalyl chloride is added, heated to reflux and reacted, and the solvent is removed to obtain imidazole-1-acetyl chloride;

[0075] II) Dissolve cyclodextrin in DMF, add triethylamine and mix uniformly, then slowly drop the imidazole-1-acetyl chloride DMF solution into the system, fully react, then wash with acetone, then redissolve with deionized water, and dry to obtain.

[0076] Further, the cyclodextrin is one of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. Example 1

[0077] The preparation method of the hydrogen-absorbing porous structure ceramic fire-resistant material of the present embodiment comprises the following steps:

[0078] 1) Take 70 mL of a 50% mass fraction of tetrabutylammonium hydroxide solution, 12 g of cotton pulp, and 30 g of DMSO, mix uniformly, then add 1.8 g of modified polysaccharide and 0.72 g of amino acid derivative, continue to mix, then fill nitrogen for foaming, continuously stir to make the gas bubbles uniformly fill the system, and vacuum to remove larger gas bubbles, then inject into the coagulation liquid through a rectangular nozzle for shaping, and wash to obtain a cellulose-based foam material;

[0079] The coagulation liquid comprises the following raw materials by weight: 10 kg of water, 1 kg of sulfuric acid, 18 g of carrageenan, 100 g of carboxymethyl cyclodextrin, 250 g of nickel nitrate, and 400 g of manganese nitrate;

[0080] 2) 10 kg of deionized water, 150 g of N-hexadecyl acrylamide, and 80 g of iron stearate are uniformly mixed to prepare a pre-solution, then 300 g of aluminum sulfate, 150 g of urea, and 30 g of fumaric acid are slowly added to the pre-solution to prepare a modified solution, then the cellulose-based foam material is soaked in the modified solution, microwave heating treatment is performed, then the template material is taken out, washed, and dried to obtain the template material;

[0081] The preparation method of the modified polysaccharide comprises the following steps:

[0082] a) 100 mL of a flaxseed gum solution with a solid content of 20% is taken, 15 g of xanthan gum and 6 g of casein are added and stirred until completely dissolved, and the pH value is adjusted to 9.0 to obtain a mixed solution;

[0083] b) 3 g of sodium tetraborate and 0.5 g of β-mercaptoethanol are added to the mixed solution, and the reaction is carried out at a temperature of 90°C for 70 min to obtain the modified polysaccharide;

[0084] 3) 500 g of ceramic powder, 173.3 g of water, 1.5 g of polyethylene glycol, 2.5 g of sodium carboxymethyl cellulose, 8 g of bentonite, 4 g of sodium polymetaphosphate, and 4 g of dioctyl phthalate are uniformly mixed to prepare a ceramic slurry, the solid content of the ceramic slurry is 75%, the ceramic powder is composed of alumina, zirconia, and magnesia in a mass ratio of 1:0.1:0.5, then the template material is immersed in the prepared ceramic slurry, the template material is uniformly wrapped in the ceramic slurry, then the excess slurry is squeezed out, the template material is immersed in the ceramic slurry again, and centrifugation is performed at a speed of 800 r / min to obtain a green body, which is dried at a temperature of 60°C for 24 h, and then sintered at a temperature of 1550°C for 3 h to obtain the ceramic material. Example 2

[0085] The preparation method of the hydrogen removal porous structure ceramic fire-resistant material of the present embodiment comprises the following steps:

[0086] 1) 70 mL of a tetrabutylammonium hydroxide solution with a mass fraction of 50%, 12 g of cotton pulp, and 30 g of DMSO are uniformly mixed, then 1.8 g of modified polysaccharide and 0.72 g of amino acid derivative are added and continuously mixed, then nitrogen gas is filled for foaming, the gas bubbles are uniformly filled in the system through continuous stirring, and the system is vacuumized to discharge large bubbles, then the system is injected into a coagulation liquid through a rectangular nozzle for shaping, and a cellulose-based foam material is obtained after washing.

[0087] The coagulation liquid comprises the following raw materials by weight: 10 kg of water, 1 kg of sulfuric acid, 18 g of carrageenan, 100 g of carboxymethyl cyclodextrin, 250 g of nickel nitrate, and 400 g of manganese nitrate;

[0088] The cyclodextrin derivative is prepared by a method comprising the following steps:

[0089] I) 0.05 mol imidazole-1-acetic acid is added to 100 mL dichloromethane and stirred until completely dissolved, then 0.0875 mol oxalyl chloride is added, heated to reflux and reacted, and the solvent is removed to obtain imidazole-1-acetyl chloride;

[0090] II) 1 mmol β-cyclodextrin is dissolved in 20 mL DMF, 3 g triethylamine is added and mixed uniformly, then 15 mL DMF solution containing 25 mmol imidazole-1-acetyl chloride is slowly added to the system, and after sufficient reaction at 25°C, it is washed with acetone, then redissolved with deionized water, and dried to obtain the product;

[0091] 2) 10 kg deionized water, 150 g N-hexadecyl acrylamide, and 80 g iron stearate are mixed uniformly to prepare a pre-solution, then 300 g aluminum sulfate, 150 g urea, and 30 g fumaric acid are slowly added to the pre-solution to prepare a modified solution, then the cellulose-based foam material is soaked in the modified solution, microwave heating is performed, then it is taken out, washed, and dried to obtain the template material;

[0092] The preparation method of the modified polysaccharide comprises the following steps:

[0093] a) 100 mL of a flaxseed gum solution with a solid content of 20% is taken, 15 g of xanthan gum and 6 g of casein are added and stirred until completely dissolved, and the pH value is adjusted to 9.0 to obtain a mixed solution;

[0094] b) 3 g of sodium tetraborate and 0.5 g of β-mercaptoethanol are added to the mixed solution, and reacted at 90°C for 70 min to obtain the modified polysaccharide;

[0095] 3) 500 g of ceramic powder, 173.3 g of water, 1.5 g of polyethylene glycol, 2.5 g of sodium carboxymethyl cellulose, 8 g of bentonite, 4 g of sodium polymetaphosphate, and 4 g of dioctyl phthalate are mixed uniformly to prepare a ceramic slurry, the solid content of the ceramic slurry is 75%, and the ceramic powder is composed of alumina, zirconia, and magnesium oxide in a mass ratio of 1:0.1:0.5, then the template material is immersed in the prepared ceramic slurry, the ceramic slurry uniformly wraps the template material, then the excess slurry is squeezed out, the template material is immersed in the ceramic slurry again, and centrifuged at a speed of 800 r / min to obtain a green body, which is dried at 60°C for 24 h, and then sintered at 1550°C for 3 h to obtain the product.

[0096] Control group

[0097] The preparation method of the hydrogen-consuming porous structure ceramic fire-resistant material of the control group comprises the following steps:

[0098] 1) Take 70 mL of 50% tetrabutylammonium hydroxide solution, 12 g of cotton pulp, 30 g of DMSO, mix well, then fill with nitrogen to foam, continuously stir to make the bubbles evenly fill the system, and then inject into the coagulation liquid through a rectangular nozzle to shape, and after washing, cellulose-based foam material is obtained; the coagulation liquid comprises the following raw materials by weight: water 10 kg, sulfuric acid 1 kg;

[0099] 2) Take 500 g of ceramic powder, 173.3 g of water, 1.5 g of polyethylene glycol, 2.5 g of sodium carboxymethyl cellulose, 8 g of bentonite, 4 g of sodium polymetaphosphate, and 4 g of dioctyl phthalate, mix well to prepare ceramic slurry, the solid content of the ceramic slurry is 75%, the ceramic powder is composed of alumina, zirconia, and magnesium oxide in a mass ratio of 1:0.1:0.5, then immerse the cellulose-based foam material in the prepared ceramic slurry, wait for the ceramic slurry to uniformly wrap the cellulose-based foam material, then squeeze out the excess slurry, then immerse it in the ceramic slurry again, centrifuge at a speed of 800 r / min, obtain a green body, dry at a temperature of 60°C for 24 h, then sinter at a temperature of 1550°C for 3 h to obtain the product.

[0100] Performance test

[0101] 1. Porosity determination

[0102] Take the porous structure ceramic fire-resistant materials of Examples 1-2 and the control group, make samples with a size of 50 mm x 50 mm x 50 mm, test the bulk density and theoretical density of the samples, and the porosity . Among them, is the bulk density of the sample, is the theoretical density of the dense material, and the results are shown in Table 1.

[0103] 2. Compressive strength

[0104] Take the porous structure ceramic fire-resistant materials of Examples 1-2 and the control group, make samples with a size of Φ20 mm x 20 mm, use a universal electronic mechanical testing machine to test the compressive strength, the speed of the pressure head is 0.5 mm / min, and the compressive strength , wherein, is the critical load, is the diameter of the sample, and the results are shown in Table 1.

[0105] Table 1 Performance test data of ceramic materials of Examples 1-2 and the control group

[0106] Sample Porosity (%) Compressive strength (MPa) Example 1 82.3±0.8 15.36±0.12 Example 2 80.8±1.2 16.82±0.07 Control 86.3±1.6 10.21±0.26

[0107] 3. Micro-morphology test

[0108] The porous structure ceramic flame-retardant materials of Examples 1-2 and the control group were taken, and the microstructure of the samples was observed using a scanning electron microscope, and the results are shown in Figures 1-3 , wherein, Figure 1 is Example 1, Figure 2 is Example 2, Figure 3 is the control group, Figure 4 is the porous foam alumina structure formed on the surface of the porous structure of Example 2. It can be seen that the porous structure ceramic flame-retardant material of the application has a more uniform porous structure, high compressive strength, and good mechanical properties.

[0109] 4. Flame combustion free radical spectrum detection of hydrogen-containing combustible gas

[0110] The porous structure ceramic flame-retardant materials of Examples 1-2 and the control group were taken, and thin plates with a thickness of 0.5 mm were prepared for standby.

[0111] The experimental apparatus includes a diffusion flame burner, hydrogen-containing combustible gas, and a spectrum data acquisition device.

[0112] The hydrogen-containing combustible gas is composed of hydrogen and methane in a volume ratio of 1:3.

[0113] The spectral range of the spectrum data acquisition device is 200-1000 nm, the resolution is 2 nm, and the scanning frequency is 200 Hz.

[0114] The nozzle of the diffusion flame burner was adjusted to face the thin plate at a distance of 20 cm, the optical fiber probe axis of the spectrum data acquisition device was aligned with the contact point of the flame and the thin plate, the gas flow rate of the nozzle of the diffusion flame burner was set to 0.05 L / s, the nozzle diameter was 70 mm, the spectrum characteristics of the flame were collected, each group of tests was performed 5 times, the spectral line intensity of the OH near-infrared band at 784.9 nm was obtained, and the results are shown in Figure 5 . It can be seen that the porous structure ceramic flame-retardant material of the application can eliminate free radicals generated by hydrogen-containing combustible gas to a certain extent, and has better flame-retardant, heat-insulating, and fire-extinguishing properties.

[0115] Although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A method for preparing a hydrogen-eliminating porous ceramic fire-retardant material, characterized in that: The steps include: 1) A quaternary ammonium solution, cellulose, and a solvent are uniformly mixed, and then a modified polysaccharide and an amino acid derivative are added and continued to mix. An inert gas is then introduced to foam the mixture, and the mixture is then transferred to a coagulation solution for setting. After washing, a cellulose-based foam material is obtained. The coagulation solution comprises the following raw materials in weight fractions: 100-150 parts water, 5-10 parts sulfuric acid, 0.15-0.2 parts carrageenan, 0.8-1.2 parts cyclodextrin derivative, 1-3 parts nickel nitrate, and 2-5 parts manganese nitrate. The preparation method of the modified polysaccharide comprises the following steps: a) taking a flaxseed gum solution, adding polysaccharide and casein, stirring until fully dissolved, and adjusting the pH to a weakly alkaline pH to obtain a mixed solution; b) adding sodium tetraborate and β-mercaptoethanol to the mixed solution, reacting at 85-95° C. for 60-80 minutes to obtain a modified polysaccharide; 2) Deionized water, N-alkyl acrylamide, and fatty acid iron salt are uniformly mixed to prepare a pre-fluid, and aluminum sulfate, urea, and unsaturated dicarboxylic acid are slowly added to the pre-fluid to prepare a modifying solution. The cellulose-based foam material is then immersed in the modifying solution, subjected to microwave heating, and then removed, washed, and dried to obtain a template material. 3) Ceramic powder, water, ethanol, binder, rheological agent, dispersant and plasticizer are mixed evenly to prepare ceramic slurry. Then the template material is immersed in the prepared ceramic slurry. After the ceramic slurry evenly wraps the template material, the excess slurry is squeezed out and finally dried and sintered to obtain the product.

2. The method for preparing the hydrogen-eliminating porous structure ceramic fire-retardant material according to claim 1, characterized in that: In the step 1), the mass volume ratio of the quaternary ammonium solution, cellulose, and solvent is (65-70) mL: (10-15) g: (20-30) mL; And / or, in step 1), the solvent is one of DMF, DMSO, and DMAC; And / or, in step 1), the amino acid derivative is one or more of phthaloylglycine, palmitoylglycine, and N-benzoylglycine.

3. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 2, characterized in that: The polysaccharide is one or more of konjac gum, pectin and xanthan gum.

4. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 1, characterized in that: In the step 2), the mass ratio of deionized water, N-alkyl acrylamide, and fatty acid iron salt is 1:(0.1-0.15):(0.05-0.1); And / or, in step 2), the fatty acid iron salt is one or more of iron palmitate, iron stearate, and iron oleate; And / or, in step 2), the N-alkyl acrylamide is one or more of N-dodecyl acrylamide, N-hexadecyl acrylamide, and N-octadecyl acrylamide; And / or, the unsaturated dicarboxylic acid is one of fumaric acid, maleic acid, and glutaconic acid.

5. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 1, characterized in that: In step 3), the ceramic powder includes aluminum oxide, zirconium oxide, and magnesium oxide; And / or, in step 3), the binder is one of polyvinyl alcohol, sodium carboxymethyl cellulose, polyethyleneimine, silica sol, aluminum phosphate, borate, sodium silicate, and potassium silicate; And / or, in step 3), the rheological agent is one of carboxymethyl cellulose, hydroxyethyl cellulose, bentonite, and kaolin; And / or, in step 3), the dispersant is one of citric acid, sodium polymetaphosphate, polyacrylamide, polyvinyl alcohol, and polyvinyl ether; And / or, in step 3), the plasticizer is one of talc powder, mica powder, and dioctyl phthalate.

6. The method for preparing the hydrogen-scavenging porous structure ceramic fire-retardant material according to claim 1, characterized in that: The cyclodextrin derivative is prepared by a method comprising the following steps: Ⅰ) Add imidazole-1-acetic acid to dichloromethane and stir until completely dissolved, then add oxalyl chloride, heat under reflux for reaction, and remove the solvent to obtain imidazole-1-acetyl chloride; II) Dissolve cyclodextrin in DMF, add triethylamine and mix well, then slowly add DMF solution containing imidazole-1-acetyl chloride into the system, wash with acetone after sufficient reaction, then redissolve with deionized water and dry to obtain the product.

7. The method for preparing the hydrogen-scavenging porous ceramic fire-retardant material according to claim 6, characterized in that: The cyclodextrin is one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

8. A hydrogen-eliminating porous ceramic fire-retardant material, characterized by: The method is as described in any one of claims 1 to 7.

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